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bruce_taylor
07-15-2009, 05:38 PM
need advice on pocketing small dadoo in 6mm sintra Have used onsrud upcut but doesn't cut the best, would like to use an o flute or straight cut.1/8 for other cuts work well but the don't have the 1/16 in the 56 series that I'm using. Any thoughts are appreciated.

myxpykalix
07-15-2009, 08:05 PM
check out www.centuriontools.com (http://www.centuriontools.com) they recently announced they have a 1/16th" bit

bruce_taylor
07-15-2009, 11:50 PM
Thanks,
Hoping someone with some firsthand knowledge could chime in on one they have had good results from, I see the onsrud 10-00, but thought I'd ask before I spent a few hundred bucks figuring it out for myself.

Brady Watson
07-16-2009, 09:45 AM
Bruce,
If a standard end mill/upcut is not getting you where you need to be, you might want to try either a 63-700 or 63-710 spiral-O. You can also use a 10-00 (2-flute straight-O) as well. As I'm sure you already know, these things are like cat wiskers...so get something with the shorted CEL you can get that works for the job at hand.

-B

bruce_taylor
07-16-2009, 09:57 AM
I'm using the 63 series and I'm fight the depth of the dado on a constant depth across the table.And they leave a small hang piece that needs to be cleaned by hand. Seems ok if I trim up the spoil board between every sheet and pay close attention as it varies a few thousands from sheet to sheet. Thought it might be the up cut pulling a little as I had noticed when I used it in other areas. I've trued the machine and it cut amazingly well looking forward to putting the 7,2 upgrade on the the xyz.

Brady Watson
07-16-2009, 10:30 AM
Bruce,
A straight will reduce the upward pull slightly, but they have a tendency to leave a lot of debris in the dado & often along the edge, necessitating cleanup. A down-cut spiral-O would give you a nice crisp top edge, but you will not get a clean bottom. Are you using vacuum to hold this down, or???

In the Summer, you really need to surface the spoilboard a little more often when you are doing precision depths. The heat & humidity wreak havok on the table, sometimes over the course of the workday.

-B

ron brown
07-16-2009, 04:11 PM
Note to picky folks:

Not all sheet material is the same thickness. Many plastics (and wood products ... and metals) vary edge to center and end to end and other ways you can't imagine until get them on a genuine flat stable surface and measure a bit.

And, yes it will vary sheet to sheet in the same lot. The dimension sander to 'fix' this was not cheap 25 years ago when I 'discovered' this.

Ron

bruce_taylor
07-16-2009, 04:49 PM
Brady,
I'm using vacuum to hold down and dealing more with the heat humidity. Thee material has about.0012 variation in the thickness.
I'm measuring what is left in the material for my control. I see the variation and just want to cut the parts to the best of my ability and as correctly as possible to deliver what my Client wants. I can see a diffeernce over the 2 1/2 hours of cutting the dado. And the 1/16 bits are FFFFragile to say the least I swear I looked at one wrong and it broke. Thinking about trying the 10-00 next. My dado is .120 in width any body know of a bit closer other than.125?
Thanks
Bruce

Gary Campbell
07-16-2009, 05:12 PM
Bruce...
try 3mm (.1181).. you will of course need a collet.

Here is an untried, but available source: http://www.positiveflow.com/cuttersm.htm

We have had 95+ degrees in the shop for the last few weeks with 90%+ humidity, round the clock. I can surface the spoilboard in the AM, run the vacs for a half hour and have the portions with airflow be .025-.030 lower. (Z mounted dial indicator) I have had to add running the vacs for an hour prior to surface to the routine.
Gary

ky_trikes
07-17-2009, 03:52 PM
And you can get a 1/2" / 3mm collet here:
http://www.rlspellmanmfg.com/bushings_sizes.html

I have tried them, and these split bushings work extremely well.
R.L. Spellman Manufacturing
PHONE: 419-381-6720
FAX: 419-381-1159
E-MAIL: sales@RLSpellmanMFG.com (mailto:sales@RLSpellmanMFG.com)
MAILING
ADDRESS:
3323 South Avenue
Toledo, OH 43609-1105

Only hitch is I think they have a $50.00 minimum, and they don't take credit cards.

majohnson
07-20-2009, 08:48 PM
For my cutting bits, I have been buying end mills bits from machine shop supply houses. Some that I have had outstanding results are, Micro 100 or Harvey Tool. The range of end mills will leave you gasping and your bank account in trouble. I have end mills ranging from .005 to .875. Anything over that I use end mills with replaceable carbide insert.

Brady Watson
07-21-2009, 09:32 AM
Spot on, Mark. I've been using Harvey & Micro100 for years...Lots of unique & hard to find tools & the carbide is top notch!

-B

bruce_taylor
07-21-2009, 11:03 AM
THANKS FOR THE TIP GUYS !!!!!!!!
Trying to identify the right bits and cutting strategy can be quit a challenge. Going to try the 3MM {.1181} as Gary mentioned. Maybe they won't be quit as fragile as the cat whiskers that the 1/16 bit are as Brady alluded to. Does any one know of a supplier of the metric bits with 1/4 inch shafts??? Or is that just asking to much of the suppliers/tool makers? Possible an opportunity?
Bruce

Brady Watson
07-21-2009, 11:48 AM
Bruce,
I am assuming that you have a Porter Cable router or similar? If you are running any of the spindles, you can get metric ER25 collets.

If running a Porter Cable, you can open up a lot of capability by purchasing a Stubby Collet Chuck. (See my write up on it here (http://www.shopbottools.com/BradysTricks.htm) ). I'm pretty sure you can get ER11 collets in metric as well. Now you have the benefit of using whatever size shank tool you want, while properly holding the tool in the router.

Also...be aware that you want to do your dado in at least 2 passes - as one pass will Climb mill one side of the slot & Conventional cut the other side. Even if you do a .005" cleanup pass it will result in a better finish.

-B

rb99
07-21-2009, 12:20 PM
Your link to the collets in the catalog is a bit confusing. Could you please find the model again?

Thanks,

RIB

majohnson
07-21-2009, 07:37 PM
Think & Tinker offer collets for the PC Router. Offering collets in 3 sizes, 1/8",1/4", and 1/2. Talking with them, they will be offering additional sizes of 3/16" & 3/8". Once the last two sizes are in production, your choice of cutters will be almost unlimited.

bruce_taylor
07-21-2009, 11:02 PM
BRADY,
I'm running a Colombo 5 hp ER25 collet just trying to keep it simple as possible. I like the onsrud 1/16 bits on the 1/4 inch shaft, and was hoping to find similar in metric. Been so busy cutting I haven't had a chance to look much yet. Looking at the harvey metal bits, What should I look at for other materials,or rather are they that different than bits made for wood,pvc,hdu etc.? At the rate I'm breaking bits in no time I should be an expert if I keep trying a few new ones to save a few bucks on shipping by ordering a minimum order.

shoeshine
07-22-2009, 12:08 AM
3/8" collets are availible from Porter Cable. I ordered one from SB with my bot as I had a bunch of 3/8" shank endmills about.

Brady Watson
07-22-2009, 08:26 AM
Mark,
Good to know about PC collets now available in those sizes.

Bruce,
Unless the tool is tapered/necked down on a taper, a 1/4" shanked 1/16" tool will be just as fragile as an industry standard 1/8" shank stepped down to a 1/16". The only difference between the two is price since you are paying 1/4" prices for a 1/16" bit. They have to start with a 1/4" solid blank before they grind it down to a 1/16". A regular old end mill is about $7 or so...how much are you paying for that 1/4" deal?

Keep in mind a few things:

Small cutters require higher RPM to get the right chipload out of them. You should be running your spindle in the 18,000-22,000 RPM range with that 1/16" cutter. It is not likely that your bit breakage is being caused by the tool overheating in PVC - which is telling me that your probably overloading the tool due to insufficient RPM. Crank that puppy up and see how it does. You should be making provisions for that delicate cutter by adjusting your VR settings to allow for a more 'cusioned' movement of the tool. This will eliminate jerks and sudden jolts that can snap that tool. I would suggest adjusting the 'Slow Corner Speed' to a value of 35 & see if that reduces breakage.

-B

bruce_taylor
07-22-2009, 08:47 AM
most of my breakage { I hate to admit} is just plain carelessness
with these fragile little bits the onsrud bits are $17 . Hit one with the wrench as I went to take it out of the collet Pretty much rookie mistakes. One I swear {literally} I no more than looked at it. I've only had one bit while actually cutting and the rpm was most likely rpm to low. I will crank it up and check my VR settings. Thanks.